The reproductive development of the eucalypt-defoliating beetles Chrysophtharta agricola (Chapuis) and C. bimaculata (Olivier) (Coleoptera: Chrysomelidae) was examined by dissecting male and female teneral, overwintering, and reproductive adults. Both species had morphologically similar reproductive systems, except that C. agricola females had more, but significantly smaller, ovarioles and C. agricola males had more testis follicles and significantly larger testes than C. bimaculata. In both species, females had ciliated lateral and common oviducts and no accessory glands. The male aedeagus of both species underwent approximately 180° longitudinal rotation during adult maturation. Both species had consistent integument and haemolymph colour changes from overwintering to reproductive maturity. Twenty percent of female C. agricola, but no C. bimaculata, had mated prior to overwintering. The rate of post-overwintering reproductive development of female and male C. bimaculata was examined at six temperatures.